This study will examine the quality and impact of PCP-performed colonoscopies on African-American patients' colonoscopy compliance, per American Cancer Society's recommendations. Colonoscopy screening is an invaluable tool to prevent 90% of approximately 145,000 annual incidence cases of colorectal cancer (CRCA) and 95% of 47,000 annual deaths in the US. This is because periodic colonoscopy can be used to detect and remove polyps, the benign precursors of (90% of) CRCA lesions, predating cancer by a decade or more. Sigmoidoscopy, till recently the screening norm, was widely performed by primary care physicians (PCPs), but it misses half of all cases because the sigmoidoscope does not reach the right colon. This discovery has caused it to be widely abandoned, without however, a commensurate increase in colonoscopies, because colonoscopy is technically more complicated, traditionally limited to gastroenterologists and colorectal surgeons. The current need for 23 million colonoscopies is nearly double the present performance of 12 million by currently available experts. African Americans (AA) have far higher case incidence, deaths, and aggressive cancers relative to whites. Moreover, they have twice the incidence of CRCA in the below-50 years age group relative to EAs, and have far higher incidence of right (ascending) colon polyps and cancers, the site that is missed by Sigmoidoscopy. For all these reasons, it is urgently necessary to increase colonoscopy screening capacity to reduce CRCA disparities. This study will'evaluate a private institution's program in South Carolina that trains PCPs in colonoscopy screening of healthy, asymptomatic older adults, followed by making available its full-service endoscopy center facility to the PCPs thus trained to conduct the procedure with an expert always available onsite to handle difficult cases. Quality and patient safety (cecal intubation rate, insertion time, withdrawal time, and complication rate (perforation, hemorrhage, and non-specific symptoms) will be assessed relative to physician's experience, patients' race, age, insurance type, and rurality, using retrospective data on 13,366 PCP-performed colonoscopies, using mixed modeling techniques. In addition, chart review will be done of patient panels of six AA trained PCPs to assess their age-eligible patients' colonoscopy compliance. This study has potential to significantly impact colonoscopy capacity in the US to rapidly reduce CRCA disparities in South Carolina and the United States. [unreadable] [unreadable] [unreadable]